The present invention relates to a motor-driven, telescopic leg and particularly to a compact assembly allowing the mounting of a drive motor within the leg.
In recent years, power-driven adjustable work surfaces, such as tables, work benches and the like, have become increasingly popular in work areas in which it is sometimes desirable to be in a seated position and at other times desirable to be in a standing position, such that table height adjustment is desirable. Utilization of power-driven telescopic legs has facilitated the adjustment of such work surfaces, and typically a pancake-type or other motor drive with a right angle connection to a jack drive screw has been employed. With such a system, the motor is external to the telescopic table leg and is typically mounted to the undersurface of the table. A right angle drive couples to a drive screw, which engages a drive nut, for controlling the telescopic motion of the table leg. Although such a system works adequately, the mounting of a motor to the undersurface of the table is somewhat bulky and unsightly. It is, therefore, desirable to provide a more aesthetically acceptable construction without the need for a motor pod mounted to the undersurface of the tables at each of the leg locations. Attempts have been made to provide a motor drive within the telescopic leg of a table, however, the drive motor occupies significant space and cannot easily be incorporated within the telescopic leg of a table in view of the space constraints.
There exists, therefore, a need for a telescopic motor-driven leg assembly in which the motor can be incorporated within the leg structure and yet provide sufficient torque for lifting a significant work surface at a reasonable speed to accommodate modern conveniently adjustable work surfaces.
The system of the present invention provides a motor-driven telescopic leg assembly providing sufficient excursion to move a table top or work surface between a lowered position and a raised position. The telescopic leg assembly includes a generally cylindrical drive motor mounted within an inner leg and is coupled in spaced relationship to a drive collar by a pedestal mount. A drive screw couples the motor to a first drive collar which is attached to the inner leg to raise and lower as the drive screw, which is threadably coupled to the first drive collar by a drive nut, is rotated by the motor. A pedestal mount extends through the first drive collar and to a second drive collar which is coupled to an intermediate leg telescopically receiving the inner leg. Gears couple the motor-driven drive screw to a rotatable power nut coupled to the second drive collar. A fixed drive screw extends from the base within an outer leg upwardly in fixed relationship through the second drive collar and receives the gear driven drive nut within the intermediate leg to raise and lower as the motor rotates the motor-driven drive screw.
By providing a pedestal mounted motor in axial alignment within the three telescopic legs at one end, the inner leg diameter can accommodate a motor of sufficient size and power to provide the desired drive forces for adjusting work surfaces providing both the excursion and drive speed necessary.
These and other features, objects and advantages of the present invention will become apparent upon reading the following description thereof together with reference to the accompanying drawings.